Homonym: γ (Radiation)
The Greek letter "γ" (gamma) is the third letter of the Greek alphabet. In the Greek numeral system, it has a value of 3. In mathematics and physics, "γ" is often used to represent various concepts, such as the gamma function in calculus, which extends the factorial function to complex numbers.
In the context of physics, "γ" is also used to denote the Lorentz factor in the theory of relativity, which describes how time and space are affected by an object's velocity. Additionally, "γ" can represent the photon in particle physics, relating to the electromagnetic spectrum and light.